So far, a drive unit using an ultrasonic motor as a drive source has been known as a drive unit using for driving a displacing element (driven element) that carries out a linear motion or a rotary motion.
This drive unit is adapted so as to transmit a vibration of a vibrating element which is excited by applying an AC voltage to a driven element, and hereby to displace (move) the driven element along a guide (for example, see Japanese Laid-Open Patent Publication No. HEI. 11-187678).
However, since the conventional drive unit includes only one ultrasonic motor, it is impossible to obtain enough drive torque.
Further, shakiness easily arises due to backlash or the like at a normal drive time, normal-reverse converting time, or the like, for example. Thus, this may make it impossible to move (displace) the driven element toward a target position accurately.